Materials Literature
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A novel technique of adsorption porometry has been developed which allows us to measure pore size distribution of a thin porous film directly on a solid substrate in a simple way. The most important principle of this technique is the use of in situ ellipsometry to determine the amount of adsorbed/condensed in the film…
Nanoparticles of poly(lactic acid) (PLA) and of blends of PLA and monomethoxypoly(ethylene oxyde) (MPEO-PLA) were prepared by the double emulsion method. Sucrose was added to overcome nanoparticle aggregation with freeze-drying. Whereas PLA nanoparticles rapidly are phagocytosed by the mononuclear phagocyte system cel…
A photo-induced electron transfer (PET) model compound in the form acceptor–fluorophore–donor and its reference compounds were synthesized. Because the fluorescence of the fluorophore 4-amino-1,8-naphthalimide (ANI) was quenched by any PET process from donor to fluorophore (PET input path) or from fluorophore to accep…
The mechanism of the OH-initiated oxidation of isoprene in the presence of NO and O2 has been investigated using a discharge-flow system at 298 K and 2 torr total pressure. OH radical concentration profiles were measured using laser-induced fluorescence as a function of reaction time. The rate constant for the reactio…
The replacement of arteries with purely synthetic vascular prostheses often leads to the failure of such reconstructions when small-diameter or low-flow locations are concerned, due in part to the thrombogenicity of the internal graft surface. In order to improve long-term patency of these grafts, the concept of endot…
We present the results of electronic-structure, abinitio calculations on a set of perovskite-structured transition metal oxides, in which the transition metal ion has electronic configuration ). We perform an analysis of the QM solution for the bulk materials, based on a phenomenological, tight binding-like examinatio…
The well known methyltrioxorhenium-catalysed epoxidation of alkenes with aqueous H2O2 is significantly improved by conducting the epoxidation in trifluoroethanol; excellent reaction rates and yields can be obtained for a variety of (terminal) alkenes with only 0.1 mol% of catalyst.
The porphyrin–crown ether derivatives described here exhibit affinities to unprotected peptides of hitherto unknown magnitude in aqueous solution; the optical signal built-in to porphyrin receptors makes these applicable also to sensor techniques; the results can also form the basis of new catalytic systems, e.g. for…
Lumazine synthase catalyzes the penultimate step in the synthesis of riboflavin in plants, fungi, and microorganisms. The enzyme displays two quaternary structures, the pentameric forms in yeast and fungi and the 60-meric icosahedral capsids in plants and bacteria. To elucidate the structural features that might be re…
A strong case has been made by several authors that sharp, spherically symmetric shocks converging on the center of a spherical bubble driven by a strong acoustic field give rise to rapid compression and heating that produces the brief flash of light known as sonoluminescence. The formation of such shocks is considere…
We report a method to fabricate Ångstrom size pores in poly(methylsilsesquioxane) films in order to decrease the density and the dielectric constant of the film. Copolymers bearing methyl(trisiloxysilyl)units and alkyl(trisiloxysilyl) units are spin-coated and baked at 250 °C to provide rigid siloxane matrixes. Films…
Point contact and tunnelling experiments performed at low temperatures were used to study the electronic behaviour of the icosahedral quasicrystalline alloys AlPdRe, AlCuFe, and AlPdMn. With samples of high quality we observed at low temperatures a zero-bias anomaly that we related to the decrease of the electronic de…
The dielectric constant and the leakage current density of (Ba, Sr)TiO/sub 3/ (BST) thin films deposited on various bottom electrode materials (Pt, Ir, IrO/sub 2//Ir, Ru, RuO/sub 2//Ru) before and after annealing in O/sub 2/ ambient were investigated. The improvement of crystallinity of BST films deposited on various…
Protein crystals contain many kinds of disorder, but only a small fraction of these are likely to be important in limiting the diffraction properties of interest to crystallographers. X-ray topography, high-angular-resolution reciprocal space measurements, and standard crystallographic data collection have been used t…
Recent results suggests that CuAlO 2 may be a p‐type transparent conductor, but thin film synthesis is difficult because of the complex Cu : Al : O phase diagram. We report a robust method of making c ‐axis oriented CuAlO 2 thin films. Thin film precursors of CuAlO 2 were deposited on sapphire (001) substrates by radi…
The versatility of the one-pot synthesis of organically modified silicas is shown by the preparation of materials with very high loadings (up to 4.85 mmol g–1) and by the synthesis of bifunctional catalysts. The synthesis of these materials is shown to be very atom efficient, with all the Si species being incorporated…
We have employed variable temperature scanning tunnelling microscopy (STM) to probe the surface structure of the TiO2(110) surface with clean, adsorbate and metal covered terminations. The aim of the work is to understand the nature of catalysis on supported metal oxide catalysts for which a good model is an admetal o…
The nucleation and growth of mesoporous silica fibers and gyroids was the focus of this kinetic study. The authors obtained images of the smallest objects implicated in the creation of these shapes by tapping-mode atomic force microscopy and transmission electron microscopy. Dynamic light scattering provided temporal…
The synthesis of a series of diphosphine ligands having phosphorus donor atoms in the core of a carbosilane dendrimer and their use in palladium catalysed allylic alkylation is described.
A three-dimensional conductive superstructure of 12 ± 1 nm Au-nanoparticles was built up on a conductive (indium-doped tin oxide) glass support by means of alternating treatments with Au-nanoparticle and cyclobis(paraquat-p-phenylene) tetrachloride solutions. The structure was characterized by absorbance spectroscopy…